So we know lasers are used to get rid of unwanted tattoos. But have you ever wondered where the ink actually goes once it's "removed"?

Well, here I'm going to tell you exactly how laser tattoo removal works, and what the hell happens to the ink that used to be there. Trust me, it's way better than what I'd imagined.

To better understand the process, I spoke with experts Dr. Hooman Khorasani, chief of the Dermatologic & Cosmetic Surgery Division at Mount Sinai Medical Center, and Dr. Randall Roenigk, professor of dermatology at Mayo Clinic, who've both done their fair share of tattoo removals for a wide range of clients.

Just as an FYI, not all tattoos are removed by laser; harder-to-remove ones need to be surgically removed.

A tattoo will be harder to remove based on things like: if it's older, if it's bigger in size, if it was done by hand (as opposed to professionally with a tattoo gun, where the ink is applied just below the skin), if it's in a place with poor blood circulation (ie. ankles, extremities, etc.), or if it includes multiple colors, Roenigk tells BuzzFeed Health. In these cases, a laser might not be able to do the job.

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Laser removal tends to be the preferred method because it usually results in the least amount of ~noticeable~ damage.

Laser removal involves creating much smaller wounds than surgical removal methods, meaning less of an inflammatory reaction and less likelihood of scarring or pigment discoloration once the skin is all healed up, Roenigk says.

But that doesn’t mean laser treatment is pain-free. "It could feel like there's a rubber band snapping your skin, which is annoying, but not terrible,” he says. “It's really not any different from getting the tattoo done in the first place. Once a session is over, it'll look and feel like a blister, or a very mild burn."

Tattoo removal often takes multiple treatment sessions because all tattoo inks are different, and each one requires a specific laser to remove it.

Inks get their color from the different chunks of minerals or metals they’re made up of — for example, black inks are usually made with iron, and yellow inks are usually made with cadmium. And it’s the chemical makeup of the ink that determines the type of laser a dermatologist needs to remove the tattoo, explains Khorasani.

"It's not uncommon for people to come in with multi-colored tattoos, where part of the tattoo responds well to a laser and other parts of the tattoo don't respond at all," he says. "That’s because every ink color is made up of different metals or minerals, which means each ink will only absorb specific laser wavelengths.”

The colors that are easiest to remove are black, brown, and blue, because those colors are the most commonly used for tattoos and there are a lot of different lasers built to remove them. But lasers are expensive and there's a limited amount of them available, so, according to Khorasani, this means dermatologists aren’t always going to have the laser required to remove a certain tattoo color.

The laser is used to heat up and subsequently break down the ink particles below the skin's surface.

Basically, when a laser is applied to a tattoo, its light penetrates the skin and gets absorbed by the ink's metal or mineral particles, Khorasani says. The absorbed light then heats up the individual particles, causing them to shatter into a bunch of much smaller pieces, like a rock exploding into pebbles.

And that's so the particles will be small enough for specialized cells to carry them away through the lymphatic system.

The word "removal" is slightly misleading, because lasers aren't actually ~removing~ your tattoos, Khorasani says. They're actually breaking down the ink particles to a size that will allow your macrophages — cells that specialize in targeting, engulfing, and getting rid of cellular debris caused by stress or trauma — to take them away from the site of injury through your lymphatic system (which collects waste material that’s in body tissues, outside the bloodstream).

“When a laser’s heat penetrates the skin it creates a wound that becomes inflamed,” says Roenigk. “And like any inflamed injury, the process of healing the wound requires macrophages to take away the fractured pigment particles, since they’re the objects that aren’t supposed to be in the body and are causing the inflammation.”

There, the particles are recognized as "waste" and discarded from your body through one of three ways — through your poop, your pee, or your sweat.

According to Khorasani, the process through which the tattoo ink leaves the body depends on the metals and minerals your ink is made up of.

“So basically, how your body gets rid of the ink is going to depend on what color it is,” he explains. “The details after that become a lot more complex. But basically, the ink will get metabolized through either your sweat glands, kidney, or liver, which means you’re literally sweating, peeing, or pooping out your tattoo’s ink particles.”

But, no, you will not be able to tell that there's tattoo ink in your poop — so please don't go looking for it.

"Yes, sometimes if you eat a food like beets, your pee could have a reddish tint to it, or if you ate kale your excrement could be green," Roenigk says. "But in this case, it's such a small amount of ink pigment that it's not going to change the color of your sweat, pee, or poop."